Question

the sum of first n, 2n, 3n,term of an ap are x y z respectively​

Answer 1

Step-by-step explanation:

Sum of first n terms = Sn = x

Let n = 1

This implies X = 1 = A1......(1)

Similarly S2n = 2n/2{2a+(2n-1)d}

or S2 = n{2(1)+(2-1)d} (as n = 1)

or S2 = 1(2-d)

or S2 = 2-d

or Y = 2-d........(2)

Similarly, S3n = 3n/2{2a + (3n-1)d}

or S3 = 3/2{2(1) + (3-1)d}

or S3 = 3/2(2+3d-d)

or Z = 3/2{2+2d)

or Z = 3 + 3d......(3)

ANSWER